Project Officer’s Report 2005
Summary and conclusions
• All five breeding waders mentioned in this report have shown a marked decline in breeding populations, which has accelerated in the last 10 years. In 2005, the breeding populations were lapwing (10 - 13 pairs) snipe (c70 pairs), dunlin (6 pairs), curlew (3 pairs) and golden plover (1 pair).
• The need for more detailed monitoring of the known populations has been identified. Observations in 2005 have provided accurate data on which to base further study and have identified several points, which will help guide future monitoring.
• The distribution of all the breeding waders has contracted over the last 10 years with many traditional breeding sites being abandoned,
• As breeding waders represent the top of a food chain, their decline indicates that factors affecting the lower levels of the food chain need to be investigated further. Significant changes to wetland plant communities and invertebrate populations have been identified, but the effects on wetland invertebrates needs further study.
• Habitat change is the most significant factor affecting both wader feeding and breeding habitat on Dartmoor. This change is linked to the reduction in grazing levels, which has occurred over recent years.
• Lack of grazing is causing the plant and invertebrate populations at breeding wader sites to be suppressed by the previous autumns growth. This is particularly noticeable in the valley mire systems and the blanket bog on the high moorland.
• The withdrawal of grazing from late autumn is a contributory factor to habitat change.
• Options available to manage vegetation within the valley mires, blanket bog and on large areas of moorland are restricted due to wet, boggy terrain and difficult access.
• The reduction of burning as a management technique in recent years has contributed to the deterioration of certain habitats. The re –introduction of a burning regime to manage habitats should be considered, however it is not a straightforward option. The increased amount of vegetation could lead to a higher risk of more intense fires causing damage to habitat and an increased risk to safety of those carrying out such controlled burns. The lack of firebreaks is a major concern on the high moor, but these may not be practical. Burning would result in increased molinia growth. This would need to be grazed following the burn to ensure that the habitat management is sustainable. Burning is not recommended on the blanket bog, however.
• Climate change may be a contributory factor to wader decline. Recent milder weather in the autumn and winter has extended the growing season for vegetation. This late growth remains ‘in situ’ until late May/early June when new growth appears.
• Breeding lapwing, curlew, snipe and golden plover are known to return to their breeding grounds in March/April. There is also growing evidence that many British bird species including waders are nesting earlier. On wader breeding habitats on Dartmoor, food availability for waders is likely to be restricted during March-May. Invertebrate activity and availability is likely to be inhibited by the thatching effect of last seasons growth.
• In 2004/05, experimental habitat management was carried out during the winter which resulted in useful and positive outcomes for breeding pairs of lapwing and curlew. Lapwings nested on the areas and a pair of curlew were observed on a site not used for 5 years.
• Predation of lapwing eggs and young was proven in 2005 to be highly significant. 3 out of 4 lapwing sites lost all eggs and chicks. Only 15% of known eggs hatched and 82% of lapwing chicks known to hatch failed to fledge. Only one lapwing site out of four produced fledged young. Carrion crows were present and suspected at all sites although other predators such as foxes were also present. Action must be taken in 2006 and 2007 to reduce crow numbers at lapwing sites. Following crow control, monitoring is essential to gather data on lapwing breeding productivity.
• The dispersal and control of foxes in and around known wader breeding sites on Dartmoor will be problematic and further restricted by the Hunting Act 2005. The Act allows fox control to be carried out to protect game birds but not wild birds including breeding waders.
• Human disturbance was not considered to be a significant factor at wader breeding sites, however further monitoring is needed. Measures to deter or reduce human disturbance at wader breeding sites need to be identified and implemented as necessary by the ‘Operation Wader’ project.
• The ten tors expedition is an annual large scale event on Dartmoor with some 2400 young people taking part in mid May. During the 2005 event, there was no obvious disturbance of the wader breeding sites, and the exclusion zones in the northern moor were avoided. Prior to the expedition, large groups of participants were observed training on the moor. Most training activity occurred in linear routes away from wader breeding sites.
• Awareness of the Operation Wader Project needs to be maintained as an ongoing project. The use of information or advisory notices positioned at wader sites to deflect visitors from disturbing breeding pairs should be implemented as part of the project strategy.
